The present invention generally relates to telecommunication systems. More specifically, the present invention relates to a method for simulating a ring back signal for a call between a calling party in one communication network and a called party in another communication network.
One known system described in U.S. Pat. No. 5,815,503 by Li, entitled xe2x80x9cDigital Simultaneous Voice and Data Mode Switching Controlxe2x80x9d, discloses a communication system that simulates a ring back signal. This known system enables a user to transmit simultaneously voice and data communication to a remote site by dynamically allocating the data bandwidth over the telephone line depending on the demands of the voice communication. First, a user establishes a data-transfer mode through the modems of two computers. In other words, a local user has its own modem and computer and a remote user has its own modem and computer. Data is transferred between these computers through their modems.
Next, the local user can transmit voice over the data transfer already in progress by lifting the local user""s handset. The off-hook condition is sensed and software sends a supervisor packet to the remote site to invoke a voice-over-data mode. The remote telephone simulates a ring to alert the remote user that a voice connection is desired. Similarly, the local telephone simulates a ring back signal to inform the local user that the remote unit is ringing. These ring and ring back signals are simulated because a connection is already established for the data transfer. In other words, a traditional ring back signal typically sent over a communication line before the connection is established cannot be sent here because the connection is already established. Consequently, the ring and ring back signals are simulated while the connection is already established and data transfer is already in progress.
The applicability of the simulated ring back signal in this known system, however, is limited because this known system provides the simulated ring back signal only after the connection is already established. In addition, because the connection is already established, this known system does not take into account the particular characteristics of the network where the remote site is located. In other words, the simulated ring back signal is generic in form and independent of the particular remote network where the remote user is located.
Embodiments of the present invention address the limits of the known system by taking into account the particular characteristic of the terminating network and by assisting in the connection of the call.
A ring back signal for a call between a calling party and a called party can be simulated. A ring back message associated with the call is received. The calling party is associated with a first network. The called party is associated with a second network. A prestored ring back signal is selected from a set of prestored ring back signals based on the ring back message and/or a called number for the call. The selected prestored ring back signal is associated with the second network and is different from a second prestored ring back signal associated with the first network. The prestored ring back signal is sent to the calling party.